1. Field of the Invention
The present invention relates to an inkjet recording apparatus and an ink determination method, and more specifically to a technique for preventing inks other than specific inks from being filled in ink cartridges.
2. Description of the Related Art
Japanese Patent Application Publication No. 2003-154734 discloses a printing apparatus capable of preventing inks other than specific inks from being filled in the ink cartridges. Each of the ink cartridges is provided with a memory in which usage information for the ink cartridge is recorded, so that it can be determined whether the ink filled in the cartridge is the specific ink or not according to the usage information. However, this configuration requires the memory installed in every ink cartridge, and it is undesirable because of increased costs.
Japanese Patent Application Publication No. 11-35863 discloses ink compositions for inkjet recording. The ink composition contains a label material such as a magnetic field generating material and a magnetizable material, so that the type of the ink composition can be determined from the label material. However, the ink contains the label material that is unnecessary for the essential functions of the ink, and it is undesirable because of increased costs and also from an ecological standpoint. Although the compositions for distinguishing inks are described in detail in the publication, the determination method is only described that the detection of the label material can be readily made with a common sensor. In particular, optically determining the infrared concentration with an inexpensive commercial sensor leads to problems with precision and stability, and there is a high probability of erroneous determination. In order to stably determine the spectra, it is required to use a monochromator having an expensive grating optical system or the like.
Using an ink other than a specific predetermined ink in the inkjet recording apparatus leads to problems with reduced image quality and reduced durability in the head and other hardware, and it is hence disadvantageous for the users.